Â鶹´«Ã½

It is often stated that the human brain is the most complex object in the universe, but is it more complex than, say, Earth’s biosphere? And how can this complexity be measured?

Herman D’Hondt Sydney, Australia

As the biosphere contains, at last count, more than 7.9 billion human brains, we can confidently state that the biosphere as an object is at least 7.9 billion times more complex than a brain.

Garry Trethewey Cherryville, South Australia

This claim has occasionally been made in articles and letters in Â鶹´«Ã½. A reader, Guy Cox, pointed out that a human body containing…